Smartphone-assisted point-of-care testing of nucleic acids based on hybridization chain reaction, magnetic beads, and gold nanorods etching

Colorimetric biosensors are simple but effective tools that are gaining popularity due to their ability to provide low-cost, rapid, and accurate detection for viruses like the Novel coronavirus, Influenza A, and Dengue virus, especially in point-of-care testing (POCT) and visual detection. In this study, a smartphone-assisted nucleic acid POCT was built using hybridization chain reaction (HCR), magnetic beads (MBs), and oxidized 3,3′,5,5′-tetramethylbenzidine (TMB2+)-mediated etching of gold nanorods (GNRs). The application of HCR without enzyme isothermal characteristics and MBs with easy separation, can quickly amplify nucleic acid signal and remove other reaction components. The blue shift of longitudinal localized surface plasmon resonance (LSPR) based on GNRs showed significant differences in etching color for different concentrations of target nucleic acid, which convert the signal into a visually semi-quantitative colorimetric result, achieving quantitative analysis with the color recognition software built into smartphones. This strategy, which only takes 40 min to detect and is two-thirds less time than the PCR, was successfully applied for the detection of the Dengue target sequence with a detection limit of 1.25 nM and exhibited excellent specificity for distinguishing single-base mutations, indicating broad application prospects in clinical laboratory diagnosis and enriching the research of nucleic acid POCT.

Hybrid Model Teaching in the Postepidemic Period: From Nucleic Acid to Antigen for the Fluorescence Analysis of SARS-CoV-2

Owing to the global spread of the coronavirus disease 2019 (COVID-19), education has shifted to distance online learning, whereas some face-to-face courses have been resumed with the improvement of the outbreak prevention and management situation, including a laboratory course for senior undergraduate students in chemical biology. Here, we present an innovative chemical biology experiment covering COVID-19 topics, which was created for third-year undergraduates. The basic principles of two nucleic-acid- and antigen-based diagnostic techniques for SARS-CoV-2 are demonstrated in detail. These experiments are designed to provide students with comprehensive knowledge of COVID-19 and related diagnoses in daily life. Crucially, the biosafety of this experimental manipulation was ensured by using artificial nucleic acids and recombinant protein. Furthermore, an interactive hybrid online-facing teaching model was designed to cover the key mechanism regarding PCR and serological tests of COVID-19. Finally, a satisfactory evaluation was obtained through a questionnaire, and simultaneously, reasonable improvements to the course design were suggested. The proposed curriculum provides all the necessary information for other instructors to create new courses supported by research. © 2023 American Chemical Society and Division of Chemical Education, Inc.

The Reduction of SARS-CoV-2 RNA Concentration in the Presence of Sewer Biofilms

Wastewater surveillance has been widely used to track the prevalence of SARS-CoV-2 in communities. Although some studies have investigated the decay of SARS-CoV-2 RNA in wastewater, understanding about its fate during wastewater transport in real sewers is still limited. This study aims to assess the impact of sewer biofilms on the dynamics of SARS-CoV-2 RNA concentration in naturally contaminated real wastewater (raw influent wastewater without extra SARS-CoV-2 virus/gene seeding) using a simulated laboratory-scale sewer system. The results indicated that, with the sewer biofilms, a 90% concentration reduction of the SARS-CoV-2 RNA was observed within 2 h both in wastewater of gravity (GS, gravity-driven sewers) and rising main (RM, pressurized sewers) sewer reactors. In contrast, the 90% reduction time was 8–26 h in control reactors without biofilms. The concentration reduction of SARS-CoV-2 RNA in wastewater was significantly more in the presence of sewer biofilms. In addition, an accumulation of c.a. 260 and 110 genome copies/cm2 of the SARS-CoV-2 E gene was observed in the sewer biofilm samples from RM and GS reactors within 12 h, respectively. These results confirmed that the in-sewer concentration reduction of SARS-CoV-2 RNA in wastewater was likely caused by the partition to sewer biofilms. The need to investigate the in-sewer dynamic of SARS-CoV-2 RNA, such as the variation of RNA concentration in influent wastewater caused by biofilm attachment and detachment, was highlighted by the significantly enhanced reduction rate of SARS-CoV-2 RNA in wastewater of sewer biofilm reactors and the accumulation of SARS-CoV-2 RNA in sewer biofilms. Further research should be conducted to investigate the in-sewer transportation of SARS-CoV-2 and their RNA and evaluate the role of sewer biofilms in leading to underestimates of COVID-19 prevalence in communities.

Influencing factors of negative conversion time of nucleic acid detection in 228 patients infected with Omicron variant of SARS-CoV-2 in Shanghai

Objective: To analyze and compare the effects of different clinical characteristics on the negative conversion time of nucleic acid detection after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection, and to provide a scientific basis for the isolation and treatment of coronavirus disease 2019 (COVID-19). Methods: The epidemiological and clinical data of 228 mild SARS-CoV-2 Omicron variant infected patients diagnosed in Shanghai were retrospectively collected from April 27, 2022 to June 8, 2022 in Wujiaochang designated Hospital, Yangpu District, Shanghai. The negative conversion time of nucleic acid detection was used as the outcome variable, and the patients were divided into A (18 days) and B (>18 days). Univariate and multivariate logistic regression analysis were used to analyze the influencing factors of the negative conversion time of nucleic acid detection. Results: The mean nucleic acid conversion time of 228 patients was (18.7+or-12.1) d, with the median time of 18 (2-46) d. Among them, 120 patients in group A had an average nucleic acid conversion time of (13.2+or-2.0) d, and 108 cases in group B had an average nucleic acid conversion time of (20.8+or-1.3) d. Univariate analysis showed that there were no statistically significant differences in the effects of hypertension, coronary heart disease, diabetes, hypokalemia, malignant tumors, neuropsychiatric diseases, chronic digestive diseases on the negative nucleic acid conversion time (P > 0.05);however, there were significant differences in the effects of combined cerebrovascular disease, leukopenia, chronic respiratory system diseases and vaccination on the negative nucleic acid conversion time (P < 0.05). Further multivariate logistic regression analysis revealed that the combination of chronic respiratory diseases and non-vaccination were significant risk factors for prolongation of negative nucleic acid conversion time (P < 0.05). Conclusions: The results of this study show that gender, age and whether hypertension, coronary heart disease, diabetes mellitus, hypokalemia, malignant tumor, neuropsychiatric disease and chronic digestive disease have no significant effect on the nucleic acid conversion time, whereas chronic respiratory disease and no vaccination are significantly correlated with the prolongation of nucleic acid conversion time in SARS-CoV-2 Omicron-infected patients.

Structural implications of SARS-CoV-2 Surface Glycoprotein N501Y mutation within receptor-binding domain [499-505]–computational analysis of the most frequent Asn501 polar uncharged amino acid mutations

The aim of this study was to evaluate the impact of the most frequent Asn501 polar uncharged amino acid mutations upon important structural properties of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) Surface Glycoprotein RBD–hACE2 (human angiotensin-converting enzyme 2) heterodimer. Mutations N501Y, N501T and N501S were considered and their impact upon complex solubility, secondary motifs formation and intermolecular hydrogen bonding interface was analyzed. Results and findings are reported based on 50 ns run in Gromacs molecular dynamics simulation software. Special attention is paid on the biomechanical shifts in the receptor-binding domain (RBD) [499-505]: ProThrAsn(Tyr)GlyValGlyTyr, having substituted Asparagine to Tyrosine at position 501. The main findings indicate that the N501S mutation increases SARS-CoV-2 S-protein RBD–hACE2 solubility over N501T, N501 (wild type): (Formula presented.), (Formula presented.). The N501Y mutation shifts (Formula presented.) -helix S-protein RBD [366-370]: SerValLeuTyrAsn into π-helix for t > 38.5 ns. An S-protein RBD [503-505]: ValGlyTyr shift from (Formula presented.) -helix into a turn is observed due to the N501Y mutation in t > 33 ns. An empirical proof for the presence of a Y501-binding pocket, based on RBD [499-505]: PTYGVGY (Formula presented.) 's RMSF peak formation is presented. There is enhanced electrostatic interaction between Tyr505 (RBD) phenolic -OH group and Glu37 (hACE2) side chain oxygen atoms due to the N501Y mutation. The N501Y mutation shifts the (Formula presented.) hydrogen bond into permanent polar contact;(Formula presented.);(Formula presented.). © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.

Effect of Some Plant Growth Hormones on the Performance of Artemisia vulgaris L. Cuttings

In the wake of the novel coronavirus (COVID-19), many plant material such as artemisia (Artemisia vulgaris L) have received renewed attention as cheap, easy-to-make treatment for many infections. However, the proliferation of artemisia from seeds is often a lengthy process. Here we investigated the role of commercial (Indol-3-butyric acid - IBA, Natural Rooting Hormone Powder - NRHP, Apple Cider Vinegar - ACV) and cottage-made (coconut water - CW and aloe vera gel - AVG) rooting hormone, and water as control (CONT) on the proliferation of artemisia cuttings in a greenhouse experiment in 2021. The survival of artemisia cuttings did not differ significantly (P > .05) across the treatments. The highest number of stems (19) and plant height (138.0 cm) was observed from CW + AVG, and the differed significantly from the others (P < .05) from the others. AVG produced the highest number of leaves per plant (1466), followed by CW (1317), CW + AVG (1278), and IBA (1241). The leaf dry weight was highest in CW + AVG, followed by those of CW and IBA. A similar pettern was observed for the root dry weight. The findings from this study showed that cottage-made plant based (coconut water and aloe vera gel) growth hormone has comparable effect to commercially available IBA on overall performance of artemisia cuttings. This study has great implications for low-tech proliferation of artemisia.

Novel Degree-Based Topological Descriptors of Fenofibrate Using M-Polynomial

Chemical graph theory is currently expanding the use of topological indices to numerically encode chemical structure. The prediction of the characteristics provided by the chemical structure of the molecule is a key feature of these topological indices. The concepts from graph theory are presented in a brief discussion of one of its many applications to chemistry, namely, the use of topological indices in quantitative structure-activity relationship (QSAR) studies and quantitative structure-property relationship (QSPR) studies. This study uses the M-polynomial approach, a newly discovered technique, to determine the topological indices of the medication fenofibrate. With the use of degree-based topological indices, we additionally construct a few novel degree based topological descriptors of fenofibrate structure using M-polynomial. When using M-polynomials in place of degree-based indices, the computation of the topological indices can be completed relatively quickly. The topological indices are also plotted. Using M-polynomial, we compute novel formulas for the modified first Zagreb index, modified second Zagreb index, first and second hyper Zagreb indices, SK index, SK1 index, SK2 index, modified Albertson index, redefined first Zagreb index, and degree-based topological indices.

US drug approvals rise in 2020 over previous year

Several medicines were approved as first treatments, including Gilead Sciences' Veklury (remdesivir) for patients with COVID-19 who require hospitalization (4);Amivas' artesunate for injection for severe malaria (5);Horizon Therapeutics Ireland DAC's Tepezza (teprotumumab-trbw), an antibody drug conjugate (ADC) for treating thyroid eye disease (6);and Ultragenyx Pharmaceutical's Dojolvi (triheptanoin) and Alnylam Pharmaceuticals' Oxlumo (lumasiran), both first treatments for metabolic disorders-Dojolvi for treating paediatric and adult patients with molecularly confirmed long-chain fatty acid oxidation disorders (7) and Oxlumo (lumasiran) for treating the rare genetic disorder, primary hyperoxaluria type 1 (8). Blueprint Medicines Corporation) for treating unresectable or metastatic gastrointestinal stromal tumours harboring a platelet-derived growth factor receptor alpha exon 18 mutation (9);Koselugo (selumetinib, AstraZeneca Pharmaceuticals), for neurofibromatosis type 1 (10);Pemazyre (pemigatinib, Incyte Corporation), for certain types of previously treated, advanced bile duct cancer (cholangiocarcinoma) (11);Tabrecta (capmatinib, Novartis) for non-small cell lung cancer that has spread to other parts of the body and whose tumours have mutations that lead to MET exon 14 skipping (12);and Retevmo (selpercatinib, Loxo Oncology, a subsidiary of Eli Lilly and Company) for treating three types of tumours with alterations of the "rearranged during transfection" gene (13). Gilead, "U.S. FDA Approves Kite's Tecartus, the First and Only CAR T Treatment for Relapsed or Refractory Mantle Cell Lymphoma," Press Release, 24 July 2020.

Potential inhibition of Melaleuca leucadendron L. compounds against the NSP5 SARS CoV-2 protein

COVID-19 is an infectious disease caused by Severe Acute Respiratory Syndrome (SARS-CoV-2), causing a global health emergency as a pandemic disease. The lack of certain drug molecules or treatment strategies to fight this disease makes it worse. Therefore, effective drug molecules are needed to fight COVID-19. Non Structural Protein (NSP5) or called Main Protease (Mpro) of SARS CoV 2, a key component of this viral replication, is considered a key target for anti-COVID-19 drug development. The purpose of this study is to determine whether the compounds in the Melaleuca leucadendron L. plant such as 1,8-cineole, terpene, guaiol, linalol, a-selinenol, beta-eudesmol and P-eudesmol are predicted to have antiviral activity for COVID-19. Interaction of compounds with NSP5 with PDB code 6WNP analyzed using molecular docking with Molegro Virtual Docker. Based on binding affinity, the highest potential as an anti-viral is Terpineol with binding energy (-119.743 kcal/mol). The results of the interaction showed that terpinol has similarities in all three amino acid residues namely Cys 145, Gly 143, and Glu 166 with remdesivir and native ligand. Melaleuca leucadendron L. may represent a potential herbal treatment to act as: COVID-19 NSP5, however these findings must be validated in vitro and in vivo.

Recent advances in the effect of ultrasound on the binding of protein−polyphenol complexes in foodstuff

Foodstuff is a complex system that consists of a variety of nutrients. Protein is the basis of human life and health, which is made up of amino acids combined in different proportional orders. Polyphenols are a class of small molecule active substances with strong pro-life health effects. It has been found that protein and polyphenols can be combined by covalent and non-covalent interactions to form complex delivery carriers. The interaction between the two can effectively improve the physiological activities of proteins and enhance the bio-accessibility of polyphenols. With the maturation of ultrasound technology, several studies have shown that ultrasound can promote the production of protein−polyphenol complexes. To promote the study of protein–polyphenol interactions in foodstuff by ultrasound technology, the preparation methods of protein−polyphenol complexes, the effects of ultrasound on complex generation, and analytical methods were systematically summarized based on an extensive literature review, and further research directions were proposed. It provides the reference for the ultrasound study of protein−polyphenol complexes.

COMPOSITION OF LIPOPHILIC COMPONENTS OF RHODODENDRON ADAMSAY ETHER EXTRACT AND ACTIVITY AGAINST SARS-COV-2 MAIN PROTEASE

The composition of the lipophilic components of the Adams rhododendron RhododendronadamsiiRehd. Acid and neutral components were identified using gas-liquid chromatography with mass spectrometric detection. Methyl tert-butyl ether (MTBE), which has all the advantages of diethyl ether, but is devoid of its disadvantages, was used as the raw material extractant. It does not form peroxides and does not create increased gas contamination due to its higher boiling point. As a result, comparison with databases identified triterpene, phenolcarboxylic and aliphatic acids with a chain length of 8 to 30 carbon atoms, including saturated, unsaturated and dibasic acids. More than 150 triterpene and aliphatic components of the unsaponifiable residue and acid fractions have been identified. Previously, unsaponifiable residues of lipophilic extracts were practically not studied. Only components of Rh.adamsiiand other species of the genus rhododendron essential oils have been studied in detail. For bioactivity testing, samples of the whole extract and its fractionation products were prepared. Some of the studied samples show inhibitory activity against the main protease of SARS-CoV-2. © 2022 Altai State University. All rights reserved.

Natural Evolution of Porcine Epidemic Diarrhea Viruses Isolated from Maternally Immunized Piglets

Simple SummaryDuring the long-term co-evolution of the virus and the host, even closely related vaccines may emerge with incomplete protective immunity due to the mutations or deletions of amino acids at specific antigenic sites. The mutation of PEDV was accelerated by the recombination of different strains and the mutation of the strains adapting to the environment. These mutations either cause immune escape from conventional vaccines or affect the virulence of the virus. Therefore, researching and developing new vaccines with cross-protection through continuous monitoring, isolation and sequencing are important to determine whether their genetic characteristics are changed and to evaluate the protective efficacy of current vaccines. The porcine epidemic diarrhea virus (PEDV) can cause severe piglet diarrhea or death in some herds. Genetic recombination and mutation facilitate the continuous evolution of the virus (PEDV), posing a great challenge for the prevention and control of porcine epidemic diarrhea (PED). Disease materials of piglets with PEDV vaccination failure in some areas of Shanxi, Henan and Hebei provinces of China were collected and examined to understand the prevalence and evolutionary characteristics of PEDV in these areas. Forty-seven suspicious disease materials from different litters on different farms were tested by multiplex PCR and screened by hematoxylin-eosin staining and immunohistochemistry. PEDV showed a positivity rate of 42.6%, infecting the small and large intestine and mesenteric lymph node tissues. The isolated strains infected Vero, PK-15 and Marc-145 multihost cells and exhibited low viral titers in all three cell types, as indicated by their growth kinetic curves. Possible putative recombination events in the isolates were identified by RDP4.0 software. Sequencing and phylogenetic analysis showed that compared with the classical vaccine strain, PEDV SX6 contains new insertion and mutations in the S region and belongs to genotype GIIa. Meanwhile, ORF3 has the complete amino acid sequence with aa80 mutated wild strains, compared to vaccine strains CV777, AJ1102, AJ1102-R and LW/L. These results will contribute to the development of new PEDV vaccines based on prevalent wild strains for the prevention and control of PED in China.

Impact of Covid-19 on the Prevalence of Intrahepatic Cholestasis of Pregnancy

Background: The virulent pathogen SARS-CoV-2 first appeared in the Chinese province of Hubei in December 2019. Pregnant women were a high-risk population in the pandemic because immune system alterations that occur during pregnancy make them more vulnerable to foreign infections. Late-pregnancy cholestasis is a dangerous liver condition that can cause the foetus to experience potentially fatal problems like early birth and stillbirth. In the present study we were testing the Bile acid level during pregnancy patients after covid pandemic. Objective(s): To evaluate the prevalence of intrahepatic cholestasis in pregnant patients after Covid -19 pandemic. Material(s) and Method(s): This cross-sectional study was conducted at department of Dr.fida painless and General Hospital Peshawar from jan 2022 to Dec 2022. We enrolled 186 pregnant patients after fulfilling the inclusion criteria. 5 ml blood sample were also taken from the patients. Serum was extracted and Bile acid test were performed in clinical laboratory. Data were collected in predesign questionnaire. Result(s): Total 186 patients were enrolled in the study with mean age of 37.18+/-6.39 years (Range 18-45 years). The mean value of all enrolled patients was 31.38+/-5.79 with minimum and maximum value of bile acids 20 micromol/L and 40.6.00 micromol/L. In our study 95 (56.5%) of patients belongs to 36 to 45 years of age group followed by age group of 26 to 35 years in which 60 (35.7%) patients and 13 (7.7%) patients were belongs to age group of 18 to 25 years. Practical implication: This study will help the clinical practitioner to take care of pregnant patients in order to avoid the prevalence of intrahepatic cholestasis. Conclusion(s): It is concluded from this research study that prevalence of intrahepatic cholestasis in pregnancy has increased after Covid-19 pandemic.Copyright © 2023 Lahore Medical And Dental College. All rights reserved.

Clinical characteristics of nucleic acid negative neonates delivered by pregnant women infected with SARS-CoV-2 in Sanya, Hainan

Objective: To explore the clinical characteristics of nucleic acid negative newborns delivered by pregnant women infected with SARS-CoV-2 (Omicron variant BA. 5.1.3) in Sanya area, and to provide evidence for understanding its clinical characteristics. Methods: A retrospective analysis was performed on 14 neonates with negative nucleic acid delivered by pregnant women who tested positive for SARS-CoV-2 (Omicron variant BA.5.1.3) in Sanya Central Hospital (the Third People's Hospital of Hainan Province) from June 2022 to September 2022 (observation group, n=14). The corresponding nucleic acid-negative newborns delivered by pregnant women detected negative with SARS-CoV-2 (Omicronon variant strain BA.5.1.3) were set as the control group (n=56), and the general data and clinical characteristics of neonates in the two groups were compared. Results: There was no significant difference between the observation group and the control group in pregnancy diabetes, pregnancy induced hypertension, gestational pre-eclampsia, fetal intrauterine distress, premature rupture of membranes (P > 0.05);there was no significant difference between the observation group and the control group in terms of sex, gestational age, birth weight, age, mode of delivery, birth Apgar score, heart screening, pulmonary disease, glucose 6-phosphate dehydrogenase (G6PD) deficiency, thalassemia, breast milk jaundice, hemolytic jaundice (P > 0.05). The bilirubin level, blue light irradiation cases and the duration of blue light irradiation of the newborns in the observation group at 7 days after birth were higher than those in the control group (P < 0.05);the ratio of blood oxygen saturation 90% in the observation group was lower than that in the control group (21.43% vs 89.29%, P < 0.05), and the ratio of blood oxygen saturation occasionally<90% was higher than that in the control group (57.14% vs 10.71%, P < 0.05). The ratio of blood oxygen saturation<90% had no significant difference compared with that in the control group (7.14% vs 0, P > 0.05), and the ratio of blood oxygen saturation reduced to the required oxygen uptake was higher than that in the control group (14.29% vs 0, P < 0.05). Conclusions: The jaundice manifestation of the nucleic acid-negative newborns delivered by pregnant women infected with SARS-CoV-2 (Omicronon variant strain BA.5.1.3) in Sanya area is relatively obvious, with blood oxygen saturation easily lower than 90% and even requiring oxygen inhalation in severe cases.

A Simple, Pipette-free, and Power-free Device for Virus Nucleic Acid Detection

A portable, inexpensive, and easy-to-manufacture microfluidic device is developed for the detection of SARS-CoV-2 dsDNA fragments. In this device, four reaction chambers separated by carbon fiber rods are pre-loaded with isothermal amplification and CRISPR-Cas12a reagents. The reaction is carried out by simply pulling the rods, without the need for manual pipetting. To facilitate power-free pathogen detection, the entire detection is designed to be heated with a disposable hand warmer. After the CRISPR reaction, the fluorescence signal generated by positive samples is identified by naked eye, using an inexpensive flashlight. This simple and sensitive device will serve as a new model for the next-generation viral diagnostics in either hospital or resource-limited settings. © 2023 SPIE.

Identification of Cyanobacteria-Based Natural Inhibitors Against SARS-CoV-2 Druggable Target ACE2 Using Molecular Docking Study, ADME and Toxicity Analysis.

In 2019-2020, the novel "severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)" had emerged as the biggest challenge for humanity, causing "coronavirus disease 19 (COVID-19)". Scientists around the world have been putting continuous efforts to unfold potential inhibitors of SARS-CoV-2. We have performed computational studies that help us to identify cyanobacterial photoprotective compounds as potential inhibitors against SARS-CoV-2 druggable target human angiotensin-converting enzyme (ACE2), which plays a vital role in the attachment and entry of the virus into the cell. Blocking the receptor-binding domain of ACE2 can prevent the access of the virus into the compartment. A molecular docking study was performed between photoprotective compounds mycosporine-like amino acids, scytonemins and ACE2 protein using AutoDock tools. Among sixteen molecularly docked metabolites, seven compounds were selected with binding energy < 6.8 kcal/mol. Afterwards, drug-likeness and toxicity of the top candidate were predicted using Swiss ADME and Pro Tox-II online servers. All top hits show desirable drug-likeness properties, but toxicity pattern analysis discloses the toxic effect of scytonemin and its derivatives, resulting in the elimination from the screening pipeline. Further molecular interaction study of the rest two ligands, mycosporine-glycine-valine and shinorine with ACE2 was performed using PyMol, Biovia Discovery studio and LigPlot+. Lastly biological activity of both the ligands was predicted by using the PASS online server. Combining the docking score and other studied properties, we believe that mycosporine-glycine-valine and shinorine have potential to be potent inhibitors of ACE2 and can be explored further to use against COVID-19.

Oral Delivery of Nucleic Acid Therapies for Local and Systemic Action.

Nucleic acid (NA) therapy has gained importance over the past decade due to its high degree of selectivity and minimal toxic effects over conventional drugs. Currently, intravenous (IV) or intramuscular (IM) formulations constitute majority of the marketed formulations containing nucleic acids. However, oral administration is traditionally preferred due to ease of administration as well as higher patient compliance. To leverage the benefits of oral delivery for NA therapy, the NA of interest must be delivered to the target site avoiding all degrading and inhibiting factors during its transition through the gastrointestinal tract. The oral route presents myriad of challenges to NA delivery, making formulation development challenging. Researchers in the last few decades have formulated various delivery systems to overcome such challenges and several reviews summarize and discuss these strategies in detail. However, there is a need to differentiate between the approaches based on target so that in future, delivery strategies can be developed according to the goal of the study and for efficient delivery to the desired site. The goal of this review is to summarize the mechanisms for target specific delivery, list and discuss the formulation strategies used for oral delivery of NA therapies and delineate the similarities and differences between local and systemic targeting oral delivery systems and current challenges.

In silico design and evaluation of a novel therapeutic agent against the spike protein as a novel treatment strategy for COVID-19 treatment.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a viral respiratory disease that is associated with severe damage to other human organs. It causes by a novel coronavirus, and it is spreading all over the world. To date, there is some approved vaccine or therapeutic agent which could be effective against this disease. But their effectiveness against mutated strains is not studied completely. The spike glycoprotein on the surface of the coronaviruses gives the virus the ability to bind to host cell receptors and enter cells. Inhibition of attachment of these spikes can lead to virus neutralization by inhibiting viral entrance. AIMS: In this study, we tried to use the virus entrance strategy against itself by utilizing virus receptor (ACE-2) in order to design an engineered protein consisting of a human Fc antibody fragment and a part of ACE-2, which reacts with virus RBD, and we also evaluated this interaction by computational methods and in silico methods. Subsequently, we have designed a new protein structure to bind with this site and inhibit the virus from attaching to its cell receptor, mechanically or chemically. METHODS: Various in silico software and bioinformatic databases were used to retrieve the requested gene and protein sequences. The physicochemical properties and possibility of allergenicity were also examined. Three-dimensional structure prediction and molecular docking were also performed to develop the most suitable therapeutic protein. RESULTS: The designed protein consisted of a total of 256 amino acids with a molecular weight of 28984.62 and 5.92 as a theoretical isoelectric point. Instability and aliphatic index and grand average of hydropathicity are 49.99, 69.57 and -0.594, respectively. CONCLUSIONS: In silico studies can provide a good opportunity to study viral proteins and new drugs or compounds since they do not need direct exposure to infectious agents or equipped laboratories. The suggested therapeutic agent should be further characterized in vitro and in vivo.

Intravenous BCAA infusion does not lead to a sustained recovery from overt HE in ACLF – An open label randomized clinical trial

Background –Hepatic encephalopathy(HE) in acute-on-chronic liver failure(ACLF) is associated with significant morbidity and mortality. We conducted a prospective, randomized controlled clinical trial to study efficacy of intravenous branched chain amino acids(IV-BCAA) with lactulose versus lactulose alone for improvement in HE at 24h, day 3 & day 7. Primary outcome was improvement in encephalopathy by ≥ 1 grade at 72 hours. Patients and Methods –EASL defined ACLF patients with overt HE were assessed and randomized into experimental arm (IV-BCAA - 500mL/day for 3 days + Lactulose;n=39) and comparator arm (Lactulose alone;n=37). Six patients developed COVID-19 after randomization & were excluded (4-experimental arm & 2-comparator arm). Results –Of 222 screened patients, 70 (35 in each arm) were included in analysis. Baseline characteristics including HE grade (2.9 ± 0.7 vs 2.8 ± 0.7;P = 0.86) and CLIF-C ACLF score (54.2 ± 5.6 vs 54.8 ± 5.7;P = 0.65) were similar. Overall survival was 40% at 28 days (48.5% vs 31.4%;P=0.14). Improvement in HESA by ≥1 grade at 24h occurred in 14 patients (40%) in BCAA arm and 6 patients (17.1%) in control group (P=0.03) which translated to shorter ICU stay. Median change in HESA at 24h was more in BCAA arm than control arm(P=0.006) which was not sustained at day 3 or 7. Ammonia levels did not correlate with grade of HE (Spearman's correlation coefficient(ρ) = - 0.0843;P=0.29). Conclusion Intravenous BCAA does not lead to a sustained improvement in HE grade in ACLF. Trial registration no NCT04238416 (clinicaltrials.gov)